Propeller surfacing machine



July 5, 1938. J. c. SHAW PROPELLER sunmcme momma Filed May 6, 1937 7 Sheets-Sheet 1 July 5, 1938. J. c. SHAW 2,122,662

PROPELLER SURFACING MACHINE Filed May 6, 1937 7 Sheets-Sheet 2 NVENTOR J76. SHAW ATTORNEY y 5, 1938. J. c. SHAW 2,122,662

PROPELLER SURFACING MACHINE Filed May 6, 1937 '7 Sheets-Sheet 3 July 5, 1938. J. Q SHAW 2,122,662

PROPELLER SURFACING MACHINE Filed May 6, 1937 7 Sheets-Sheet 4 INVENTOR J.' C. SHAW July 5, 1938. J. c. SHAW PROPELLER SURFACING MACHINE Filed May 6, 1937 7 She'ets-Sheet 5 INVENTOR J. C 674A w ATT RNEY July 5, 1938. J. c. SHAW PROPELLER suamcme mxcam:

Filed May 6. 1957 7 Sheets-Sheet 6 INVENTOR J'C. SHAW ATT RNEY July 5, 1938. J. c. SHAW PROPELLER SURFACING MACHINE 7 Sheets- Sheet 7 Filed May 6, 1937 Patented July 5, 1938 UNITED STATES 2,132,862 raoramaa suaracmo moms John 0. Shaw, use, Conn., assignor to. Niles- Bement-Pond Company, Hartford, Coma, a corporation of New Jersey Application May 6, 1937, Serial No. 141,132

8Claims.

This invention relates to propeller surfacing machines and particularly to a machine for surfacing opposite faces of marine propeller blades of large size. 5 Anobject of the present invention is to provide a machine having a tracer and cutting tool, the

tracer being movable over a template corresponding to a surface of the propeller blade and the tool being guided in its movements over the 10 blade by means associated with and controlled by the tracer and its contact with the template.

Another object of the invention is to provide a turret rotatable as a unit upon a vertical axis.

and disposed coaxially with-the propeller being 15 finished, the turret providing means for movably mounting the supports carryingthe tracer and cutting tool respectively for movements radially toward and from the axis of the turret and vertically up and down. 20 Another object of the invention is to provide mechanism for oscillating the turret about its axis through varying arcs depending upon the width of the propeller surface being finished, this oscillatory movement taking place simultaneously with movements vertically of the tracer and tool in accordance with the template or model being followed, feeding means beingprovided to suecessivelymove the tracer and tool radially a short distance either toward or from the axis between 30 each oscillatory movement of the turret.

A feature of importance of the invention also is the application of the control mechanism and electric circuits shown and described in my Patent 1,683,581 granted September 4, 1928 to a pro- 35 peller surfacing -machine without substantial modification or addition.

And finally it is an object of the invention provide a reducing means between the tracer and the tool enabling a smaller and more convenient 40 template to be used than the propeller being finished so that the distances moved by the tracer may be materially less than those of the tool.

With the above and other objects in view, my

invention consists in the features of construction and operation set forth in the following speciflcae tion and illustrated in the accompanying drawings.

In the accompanying drawings annexed hereto and forming a part of this specification, I have 5 shown the invention embodied in and adapted for a surfacing machine for propellers of extremely large size but it will be understood that the inventlon can be otherwise embodied and that the drawings are not to be construed'as defining or 55 limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Figure 1 is a complete side elevation of a propeller finishing machine made in accordance with v 5 the present invention, parts being shown in section for better illustration.

Fig. 2 is a vertical sectional view of the complete machine taken upon a plane at right angles to Fig. 1.

Fig. 3 is a plan view of the machine, one side being broken away.

Fig. 4 is a front elevation of the cutting tool and mounting therefor.

Fig. 5 is a side elevation of the parts shown in Fig. 4.

Fig. 6 is an enlarged view of parts shown in Fig. 2, this figure showing the tool carriage and its controlling mechanism for moving the carriage radially and for moving the tool spindle therein vertically.

Fig. 7 is a view similar to Fig. 6 and showing the means for moving the tracer support radially and for moving the tracer bar vertically.

Fig. 8 is a detail view in section showing the 5 tool mounting end of the tool spindle upon an enlarged scale over Fig. 5.

Fig. 9 is a detail section through the track; upon which the turret revolves.

Fig. 10 is a cross sectional view taken on the plane of line Iii-II of Fig. 6; and

Fig. 11 is a cross sectional view taken on the plane of line il--il of Fig. '1.

In the above mentioned drawings there has been shown but one embodiment of the invention which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention. 40

Briefly and in its broadest aspect the invention may include the following principal parts: First,

a fixed circular track or guideway surrounding a pit or excavation within which the propeller being surfaced may be centrally mounted; second, a turret rotatably mounted thereon; third, means to revolve the turret in either direction; fourth, supporting means within the excavation or pit so that the propeller being finished may be coaxial with the axis of rotation of said turret; fifth, a tool supporting carriage movable substantially radially on said turret; sixth, a tool head vertically movable within the carriage; seventh, a cutting tool rotatably mounted and extending from the lower end of said head; eighth, a template as mounted independently of the turret and ind able about the guideway to successive angularpositions; ninth, a tracer supporting carriage movable substantially radially on said turret; tenth, a tracer carrying slide movable vertically in said latter carriage; eleventh, a tracer in the slide adapted to contact said template during operation; twelfth, means preferably in the form of electric circuits and controlled by engagement of the tracer with the template for raising and lowering the tracer and cutter in conformity therewith as the turret is oscillated between predetermined limited angular positions; and thirteenth, means to feed the tracer and cutter successively to different radial positions after each oscillatory movement of the turret.

The surfaces on opposite faces of the blades of marine propellers are generally helicoidal but depart from the exact surface of a helicoid, each side having its own modifications to provide sufficient strength in the different portions of the blade and for other purposes. The present machine does not and is not designed to generate an exact helicoidal surface on a blade but operates upon a system of copyins and enlarging from reduced templates having the forms respectively of surfaces to be reproduced for each face of the blades. The templates can be originated in any manner or by any process forming no part of the present invention and preferably may have arcuate surfaces the upper edges of which conform to closely spaced portions of the desired blade surface but upon a'reduced scale. As the surfaces on opposite faces of each of the blades of a propeller are similar to the others, but two templates are required for any one propeller, one for each face of the blades.

Referring more in detail to the figures of the drawings, I provide a turret ll adapted to rotate about circular guideways H forming a track surrounding a pit l2. Preferably the circular ways II as shown in the drawings are provided on the upper horizontal surface of a massive concrete foundation l3 forming the wall of the pit l2. The excavation or pit l2 provided within the ways II is sufllcient in diameter and depth to accommodate the maximum size propeller W to be finished upon the machine presently to be described. On the turret I I are provided bearing rollers l4 supported on and depending from the lowermost surface, there being a number of these rollers I! placed about the periphery of the turret I II and bearing upon the upper surface of the circular track or ways ll. These bearings support the entire weight of the turret and parts thereon. Adjacent each of these hearing or pressure rollers H are opposed pairs of rollers II engaging the outer and inner periphery respectively of the circular ways II. By means of the fixed circular ways II and the rollers I4 and I! the turret Iii may be revolved centrally above the pit l2 about a fixed vertical axis and with minimum friction.

In order to effect rotation of this turret Ill there is provided a driving chain it loosely surrounding the outer surface of the circular ways II. This chain it may be supported in position by means of spaced angle irons ll outstanding from and secured to the ways II. This chain it is engaged by driving sprocket wheels ll, these wheels being mounted on the lower ends of vertical driving shafts 19. Preferably, adjacent the driving sprocket wheels I! for this turret III are idler wheels or pulleys 2!! adjustable substantially radially in any preferred manner as indicated in Fig. 3 so that the chain ll may be tightened aboutthe ways II. By rotating the sprockets II by any suitable means the turret II will be rotated, there being locking means or sufficient friction of the chain It against the outer surface of the circular ways II to prevent rotation of the chain relative to the track.

The driving means for the sprocket wheels ll shown in Figs. 1 and 3 may comprise a small motor 2| constantly driven in one direction, op-' posed clutches 22 being driven thereby and adapted to rotate a pinion 28 in opposite directions depending upon which of the clutches 22 is engaged. This motor 2| and opposed clutch mechanism 22 are in every way similar to corresponding parts shown in Figs. 13 and 14 of the drawings in my above-referred to patent. It will suflice to state that upon energization of an appropriate control circuit one or the other of the clutches 22 is energized. This drivingly connects the motor 2| with the pinion 22 through that particular clutch to rotate this pinion 22 and the turret ii in one direction. As soon as the turret III has been revolved to a predetermined position that particular clutch may be deenergized and the opposite clutch energized to rotate the pinion 22 and the turret III in the opposite direction.

Between the driving pinion 23 and the sprocket wheels I8 is a -difl'erential mechanism 24 connected as shown in Figs. 1 and 3 to substantially radially mounted shafts 25 extending to the periphery of the turret l0 so that the load is equally divided between the shafts 26. By suitable gear connections between these horizontal radial shafts 2i and the sprockets It at the lower ends of shafts l9 and suitable controlling mechanism which presently will be referred to, the turret l0 may be oscillated through 'dliferent angles about the central vertical axis of the machine as desired in either direction and at any desired speed. The direction and extent of oscillation will. depend upon the operation of suitable switches controlled by electric circuits similar to those described in the above-referred to patent. As the controlling and operating circuits, switches, etc... for controlling the direction, speed and extent of movement of the turret III by the above-described connections form no part of the present invention, further description is not thought necessary.

The propeller W to be machined may be mounted centrally within the pit or excavation I2 andsupported in fixed position while its entire blade surfacing operation upon one side is being completed. As shown, a central shaft 26 extends through the hub of the propeller W and has its lower end resting within a conical seat in a member 21 set into the floor of the pit ID. The securing means for the propeller are not shown or described but may be of any type facilitating removal and replacing of the propeller W within the pit l2 in opposite or inverted position.

To eifect placing of the propeller W in its centhe engagement of the rollers I5 at its periphery with the surfaces of the circular ways H.

Preferably the template 30, the form of which is to be duplicated upon a larger scale on the blade surfaces of thepropeller, as shownin Fig. 2, maybe built up of a plurality of arcuateplates of relativelythin metal such as steel sheets vertically disposed in closely adjacent concentric positions. Each plate of the template It has its upper edge cut away so that the surface formed by upper edges of the entire group of plates will correspond to the surface desired to be reproduced in materially enpropeller being machined. The variations in heights of the plates of template are or may be similarly reduced relative to the variations in height'of the surfaces being machined. If desired, however, one scale of reduction may be used for the radial and arcuate dimensions of: the template 30 relative to those of the propeller W and the same ora different scale of reduction may be used for the heights of the template surfaces compared with the variations in height of the propeller W.

The template 30 is supported in position and radially disposed relative to thepropeler W upon and by means of an angularly adjustable or indexable arm 3|. The template supporting arm 3i may at one end he supported centrally of the propeller W and for convenience may swing about the central stud or shaft 28 which passes axially through the propeller hub. The outer end of the arm 3| may be supported upon suitable roller bearings 32 and 33 engaging the fixed circular track II respectively upon its horizontal and vertical inner and outer surfaces. These bearings 32 and 33' may be similar in every way to the bearings I 4 and I! respectively, there being one or more rollers 32 resting on the upper or horizontal surface of the circular track ii and one or more pairs of rollers I3 engaging the inner and outer surfaces. means (not shown) are provided for the template supporting arm 3i so that the arm I and template 30 may be secured in proper angular positions in accordance with the blades being surfaced in successive positions for corresponding surfaces on each blade. In operation upon any surface of the propeller the arm ii and the template 30 are retained in fixed position. When operation upon the corresponding surface of another blade is to be started the arm II is indexed about the circular track II to a new radial or angular position properly disposed for the second blade and secured in that position during the cutting operation upon that surface.

The tracer 35 adapted to contact with the upper surfaces or edges of the plates forming template 30 may be similar in every way to the automatic electric tracer shown inFig. 16 of my abovereferred to patent. The tracer bar or lever, however, in the present instance, is in a vertical rather than horizontal position and is secured to a vertically movable slide ll mounted within.

a head '31. The tracer supporting head 31 is movable along horizontal ways substantially .radially disposed on the turret II. The means for controlling the radial position of the head 31 and the vertical position of the tracer slide 38 and tracer 35 may comprise electric control circuits corresponding to those used for the same pur-. poses in the above-referred to patent. The connections between the tracer 3i and cutting tool In addition suitable clamping turret Ill referred to above.

ll so that movements radially and vertically of the tracer will be transmitted in proper coordinated relation to the tool will presently be described. 4 1

The head 31 is moved step by step to successively diflerent radial positions after each oscillatory movement of the turret ll, each radial movement causing the tracer 2! to contact with the upper edge of an adjacent template plate 3|. These movements are controlled and effected by electric circuits corresponding in every way to those for traversing and feeding the tracer and tool shown and described in the above-referred to patent. Fig. 7 shows the mechanism for moving the tracer I! vertically with its slide it and horizontaliyor radially on the turret II with the slide II and head 31. The slide 38 is provided with an elongated screw 38 extending longitudinally and secured to the slide as against endwise and rotary movement. Engaging this screw 38 is a nut 3| rotatable within the head or carriage 31 but held against axial movement by any suitable means. On the nut 39 are bevel gear teeth meshing with, the teeth of a companion bevel gear 40. Gear it is rotatably mounted-in the head 31 but retained against endwise movement. To rotate the gear It and thus raise or lower the tracer I! there is provided an elongated splined shaft 4i within the turret l0 disposed parallel to the direction of movement of the head 31. To move the carriage or head 11 radially toward and from the axis of the turret it there is provided an elongated screw 42 engaging within a nut fixed 1 within the carriage 31. Means to rotate the screw 42 and splined shaft ll will presently be described.

The cutting tool 45 is supported within a carriage substantially radially movable on the thereon radially toward or from the axis of theturret II a screw ll extends substantially radially of the turret. This screw is held against axial movement within carriage 4! and may be rotated in either direction by means presently to be described. The screw it is engaged by a nut ll fixed to and depending from the carriage.

Vertically slidable within the carriage 48 is a tool supporting slide or head It. A screw ll, extending longitudinally of the slide I0 and supported in the slide against rotation and endwise movement is engaged by a nut 52 rotatably supported within the carriage 46. By rotation of this nut I through the clutch driving connections and motor 53 shown in Fig. 5 the tool 4! may be raised and lowered. The motor 53 shown in Fig. 5 of the drawings controls the rotation of the nut 52 in either direction through oppositely rotating clutches of magnetic type and driving connections similar to the clutches for oscillating The direction of rotation of the nut 52 to raise or lower the tool is'controlled by energizing one or the other of the clutches through the electric controlling circuits described and shown in' my abovereferred to patent.

To raise and lower the tracer 35 and tool ll simultaneously the motor 53 and driving means for rotating the nut 52 are connected by gears 55 to a spline shaft 83 disposed parallel to the direction of movement of the head 46. By suitable sprocket gears 84 and chain spline shafts II and '3' are rotated simultaneously relative amounts. By choosing a diflerent and longer II lead for the screw 5| than for the screw 88 the vertical movement of the tool .5 may be made greater than corresponding movements of the tracer 85. By this meam the vertical dimensions of the tracer 88 may be materially reduced relative to the vertical heights of the propeller blades being surfaced. It will be understood that by means of controlling circuits opened and closed by contacts on the tracer 85 the screws 88 and 55 will be rotated. reversed or stopped for varying short intervals of time in accordance with the variations in elevation of the different parts of the template 8!.

Screws 42 and 48 controlling the radial positions respectively of tracer 85 and tool 45 are coupled together by sprocket wheels 85 and chain 61. By choosing proper leads for the screws 42 and 48 and different diameters for gears 58 radi'ai movements of the tracer 85 may be reduced any desired amount relative to corresponding movement of the tool 45.

As the tool carrying slide 50 and parts mounted thereon are of considerable weight, counterbalancing means therefor are provided. 'I'hese means preferably are in the form of cylinders 55 secured to the slide 50 having pistons 58 secured to the carriage 48 on which the slide is supported. By admitting air to the cylinders 55 above the pistons 55 at a constant predetermined pressure the vertically moving weights may be compensated by pneumatic pressure without adding materially to the total weight carried by the carriage 46.

Within the tool carrying slide 50 is a longitudinally disposed tool rotating shaft 58 adapted to be rotated at relatively high speed as by a motor 59 mounted at the upper end of the slide 58. Motor 59 may be drivingly connected to the shaft 58 by any desired gear connections (not shown) by means of which the speed of rotation of the shaft 58 may be controlled. The lower extreme end of the shaft 58 is provided with a bevel gear 50 secured thereto in mesh with a bevel gear 5| on the inner end of an obliquely extending shaft or spindle 62 suitably supported for rotation within the slide 50. This spindle 82 has provision at its outer end for holding a cutter 45 such as a round nosed milling cutter of the type usually employed in die-sinking operations.

To limit the oscillatory movements of the turret In there may be mounted a reversing switch M which for convenience may be mounted on the extension of the turret l on which the tracer carriage 31 operates. To operate switch I8 adjustable dogs H may be provided in the path of movement of the switch 18. Dogs H may be mounted on a bracket I2 secured to the tempiate carrying arm 3|. As shown in Fig. 7, the dogs engage a T-slot provided in the upper surface of the bracket 12 along which the dogs may be adjusted and clamped in any position. With the switch 10 mounted on arm 3| the turret ID will be oscillated between proper limiting positions for operating upon each of the blades of the propeller for the reason that indexing of the arm 8i for ezlich blade will correspondingly index the dogs I Between each oscillatory movement of turret ill the shaft 48 must be rotated to radially position the tracer 35 and tooi 45 to traverse different arcuate paths over the template 30 and propeller W respectively. This rotary movement of the shait 48 may be effected by a suitable motor 14 conveniently mounted on the outer end of turret l0 and connected to the shaft 53 by means of pinion 15 on the armature shaft of motor 14 which meshes with a gear 18 secured directly to the outer end ofshaft '48.

In operation the propeller W isilrst located within the pit l2 centrally thereof so that its central axis will be vertical and coaxial with the track ll upon which the turret J0 revolves. The. propeller W is then secured in its central position by any appropriate means (not shown). The turret I8 is mounted in positien upon its track ll and its driving chain II, which loosely surrounds the fixed track I], is placed in mesh with the driving sprocket wheels l8 and the idlers 20 adiusted so that the chain will frictionally engage the outside surface of the fixed track.

The template 80 is then positioned on the radial arm 8| and the arm placed in proper angular position as shown in Fig.2with its ends respectively mounted on the central shaft 28 and on the track II. The arm 8| is then adjusted to the proper angular position above one of the blades being finished so that the tracer 85 will engage a portion of the template 88 when the tool 45 is in position to operate on the portion of the propeller. blade W corresponding to the portion of the tem- .25 plate engaged by the tracer.

The cutting operation can now talre place during which the turret I0 is slowly oscillated about the track ll back and forth while the tracer 85 passes over arcs about the surface of the blade being finished. After each oscillatory motion of the turret in each direction the tracer 85 and cutter 45 may be moved radially outward. These oscillatory and radial movements of the tracer 85 and tool 45 alternate until the entire surface of .35 the blade has been traversed and its surface made to conform to that of the template but upon an enlarged scale.

To start the cutting operation on another blade the arm 8| and the template 80 thereon are indexed angularly about the axis of the turret l0 so that the template 80 will be disposed above another blade to properly locate the tracer 35 for operation of the cutter on the second blade. This blade may then be finished in the 45 same manner as the first blade and the remaining blades may then be successiveiy finished by again indexing the arm El and oscillating the turret I 0 between different angular positions.

After one face of each of the blades has been finished the turret Ill is lifted ofl. its track II and the propelier W inverted, thus presenting the opposite sides of the blades to the cutting tc-ol 45. As the opposite sides of the propeller blades are or may be of different contour this side is finished with its own template different from and replacing the first template on the radial arm 8|.

What I claim is:

l. A propeller surfacing machine comprising in combination, means to support a propeller in}. fixed position, a turret mounted for rotation coaxially with said propeller, a tool carriage movable substantially radially on said turret, a tool siide vertically movable on said carriage, a tracer supporting carriage on said turret, a vertically movable tracer therein, a model conforming to a plurality ef arcuate contours of a blade and supported in fixed pesition below said tracer, means controlled by contact of said tracer with said model for raising and lowering said tool slide,, means to oscillate said turret during operation of said tool, and means to move said traeer and tool slide in predetermined relation to each other.

2. A propeller surfacing machine comprising in combination, means to support a propeller in fixed position, a turret mounted for rotation co-.

axially with said propeller, a tool'carriage movable substantially radially on said turret, a tool slide vertically movable on said carriage, a tracer supporting carriage on said turret, a vertically movable tracer therein, a model conforming to a plurality of arcuate contours of a blade and supported in fixed position below said tracer, means controlled by the contact of said tracer with the model for raising and lowering said tool slide, means to oscillate said turret during operation of said tool, and means to periodically move said tracer and tool slide short distances radially in predetermined relation to each other.

3. A propeller surfacing machine comprising in combination, means to support a propeller in fixed position, a turret mounted for rotation coaxially with said propeller, a tool carriage movable substantially radially on said turret, a tool :0 slide vertically movable on said carriage, a tracer supporting carriage on said turret, a vertically movable tracer therein, a model conforming to a plurality of arcuate contours of a blade and supported in fixed position below said tracer, means :5 controlled by the contact of said tracer with the model for raising and lowering said tool slide in accordance with movements of said tracer, means to oscillate said turret during movements radi ally of said tool to traverse said tracer and cutter so respectively over said model and propeller, and

means to advance said tracer and cutter to successively different paths over said model and propeller.

4. A propeller surfacing machine comprising in 35 combination, means to mount a propeller and cutter for relative movement whereby said cutter may traverse the entire surface of a blade of said propeller, a model and tracer mounted for relative movement whereby said tracer always en- 49 gages a portion of the model corresponding to the portion of the propeller engaged by the cutter, and means to advance and retract said cutter and tracer in accordance with the contour of said model during the traversing respectively of the 5 model and propeller.

5. A propeller surfacing machine comprising in combination, a pit within which a propeller may be centrally mounted and retained in fixed position, a circular track surrounding and concentric with said pit, a turret rotatable on said track, a

rotatable cutter on said turret mounted for radial and vertical movements, a model conforming to a plurality of. arcuate contours of a blade and mounted in predetermined position relative to said propeller, a tracer mounted on said turret for arcuate movements over said model, and means to oscillate said turret to traverse said cutter over the propeller.

6. A propeller surfacing machine comprising in combination, a pit, means to centrally position and retain a propeller therein, a circular track surrounding said pit, a turret rotatable upon said track coaxial with said propeller, a sprocket chain surrounding said track. a sprocket wheel on said turret engaging said chain, and means to rotate said sprocket wheel in opposite directions to oscillate said turret.

7. A propeller surfacing machine comprising in combination, a pit, means to centrally position and retain a propeller therein, a circular track surrounding said bit, a turret rotatable upon said track coaxial with said propeller, a sprocket chain surrounding said track, a sprocket wheel on said turret engaging said chain, adjustable idler wheels on said turret engaging said chain whereby the chain may be tightened about said track, and means to rotate said sprocket wheel in opposite directions to oscillate said turret.

8. A propeller surfacing machine comprising in combination, a pit, means to centrally position and retain a propeller therein, a circular track surrounding said pit, a turret rotatable on said track, bearing rollers on said turret contacting with the upper surface of said track, rollers on said turret engaging the inner and outer surfaces of said track, a sprocket chain surrounding said track, driving means on said turret engaging said track for rotating said turret, and means to disengage said driving means from said track whereby said turret may be removed from said track. 

